This invention relates generally to railway brake systems and relates more particularly to such a system which is air-actuated.
During the course of preparing a train of railway vehicles for travel at a railroad yard, the railway vehicles may be required to be uncoupled from one another for movement either singularly or in small groups of vehicles across a hump for subsequent couplement of the railway vehicles together in a prescribed order. Commonly, each railway vehicle in a train within which an air-actuated braking system is incorporated includes a brake line which is appropriately coupled to the brake line of every other vehicle in the train. Hence, when adjacent railway vehicles in the train are uncoupled from one another, the brake lines of the adjacent vehicles must be uncoupled as well so that subsequent recouplement of the railway vehicles together requires that the brake lines be recoupled and precharged to a prescribed pressure before the vehicles are returned to the service.
A charging operation of the brake lines of coupled railway vehicles is effected with the use of a compressed air source and is normally carried out in two phases. The first, or voluming-up, phase of the charging operation is carried out as the brake lines are coupled together and the second, or pressuring-up, phase is carried out while the coupled brake lines are sealed from the atmosphere and the internal pressure of the brake lines is raised to the prescribed pressure.
The voluming-up phase of the charging operation commences when the brake line of a first vehicle in the train is operatively coupled to the source of compressed air, such as may be supplied through trunk lines of a railroad yard from a powerful compressor of a type commonly situated at the yard, so that air from the source is directed through the brake line of the first vehicle and into the atmosphere. Equipment related to the brake line, such as piping and reservoirs, are thereby connected in flow communication with the compressed air to the brake line. The brake lines of adjacent vehicles are then coupled in sequence in an end-to-end fashion beginning with the brake lines of the first and a second of the railway vehicles and ending with the coupling of the brake lines of the next-to-last and last railway vehicles in the train. Upon coupling the brake lines of two adjacent vehicles, an operator performing the coupling operation ensures that the flow of air through the coupled brake lines is continuous by sensing the blowing of the air out of the uncoupled end of the coupled lines.
The pressuring-up phase of the charging operation commences when the brake line of the last railway vehicle in the train is sealed so that as air from the compressed air source continues to flow into the coupled brake lines, the internal pressure thereof begins to increase appreciably. When the internal pressure of the coupled brake lines reaches the prescribed level, and appropriate testing of the braking equipment is completed, the yard source of compressed air is disconnected from the brake line of the first vehicle and the railway vehicles await the locomotive source of compressed air.
A limitation associated with a conventional charging operation such as aforedescribed relates to the utilization of air under high pressure during the voluming-up phase of the operation. By supplying air at a high pressure to the brake lines, the energy expended and the related costs involved in the production of the high pressure air for the voluming-up phase of the operation are unnecessarily high.
Accordingly, it is an object of the present invention to provide a new and improved method and apparatus for charging the brake lines of a train of railway vehicles which conserves air from a source of compressed air.
Still another object of the present invention is to provide such an apparatus which automatically switches between voluming-up and pressuring-up modes of operation.
Yet another object of the present invention is to provide such an apparatus for preventing an appreciable loss of compressed air if a brake line were to rupture during the pressuring-up phase of a charging operation.
A further object of the present invention is to provide such an apparatus which reduces energy and labor costs involved in a brake-charging operation.
A still further object of the present invention is to provide such an apparatus which can save time during a brake-charging operation.
A yet further object of the present invention is to provide such an apparatus which enhances the safety of a brake-charging operation.
One more object of the present invention is to provide such an apparatus which is uncomplicated in construction and effective in operation.